eMagStudio currently offers no "plug and play" solution for adding tabs that navigates a publication. However, several approaches can be taken by users who wish to replicate this effect. Basically the fundamental approach will be one of the following:
Create the tabs using images or flash elements, combined with the Action & Event system
Create a custom Flash component, and use the SWFHolder API to create the communication between the Flash code and the eMagStudio's Action & Event system
For most users, solution 1. will by far be the easiest one to accomplish, and really only requires a basic understanding of the Anchoring system (to learn more, we recommend this tutorial) as well as the basic use of the Event & Action system. Simply add a set of image of Flash elements to the Foreground or Background layer of your eMag. Anchor them to the edge of the Page View, and assign them the Events needed to navigate to the relevant pages.
Taking the solution one step further, requires a solid understanding of ActionScript, Flash and eMagStudio, and basically implies that you create your entire tab-bar in Flash and then "wire-up" the interactivity you have created with the SWFHolder API, using the EMSMediator.instance.doBroadcast function. To learn more about this, study the examples provided in the developer folder that comes with eMagStudio (to open, select Help -> Advanced -> Developer tools from the main menu), and take a look at this example video.